I learned this song years ago from the above LP - the last time I sang it was in Mystic last year. My memory of the last two verses is slightly different:

Above version: "The fan's on the bum and fire won't draw"

I have: Then the port fan broke, and the fire wouldn't draw.

Also "finished" for "buggered"....

But in both cases the earthier version has something going for it.

"So come all you firemen, listen to me
The Mauretania spells purgatory..."

I sing:
Come all you trimmers and listen to me
That Cunard ground's bloody purgatory

Though of course I might easily have mislearned or misremembered it in classic traditional style.